I have no direct experience with painting bottle labels, but as an artist I have much experience with both paint and glass. If you want to use a paint directly on the bottles that will stand up to hand washing and refridgeration, there are special enamels available at your craft store or stained glass supplier that can be baked on in your oven. If you have blank labels or printed labels that you've primed (preferably with "gesso"), most any paint should be fine, especially if covered with a clear, glossy sealer, but I would still recommend an enamel. Waterbase enamels (acrylic or latex)are fairly inexpensive, easily cleaned, and relatively durable. You may encounter problems with any waterbase paint sticking to printed labels. If so, you might try lightly sanding with a very fine git paper first. Good luck!